A large body of research has established that most aspects of the narcolepsy syndrome can best be understood as a disorder of REM sleep. Studies in cats have identified the neuronal Groups critical to REM sleep control. However, it is not known how these groups malfunction in the narcoleptic animal. We propose to conduct the first studies of the activity of pontine cells in the narcoleptic dog. Unit activity in "REM sleep-on", "REM sleep-off" and PGO (Ponto-geniculo-occipital) spike related cells will be examined during natural sleep and waking states in unrestrained narcoleptic dogs. We will determine the direction and time course of activity change in these cells during cataplexy and waking states. We will determine the response of these cells to treatments known to increase or decrease cataplexy. We will determine their projection pattern, conduction velocity and sensory responses. Not only will an analysis of pontine activity in the narcoleptic dog increase our understanding of narcolepsy, but it is also likely to provide fundamental insights into the mechanisms responsible for the regulation of REM sleep, muscle tone and arousal processes in the normal animal. We have extensive experience with all of the required techniques and have demonstrated their feasibility in studies in the medulla of the narcoleptic dog.